Placement of the Bravo wireless pH monitoring capsule onto the gastric wall under endoscopic guidance

BackgroundThe Bravo system was designed mainly to monitor esophageal pH, and there have been no reports on gastric pH monitoring using this system.ObjectiveTo place the Bravo capsule on the gastric wall and monitor gastric pH.DesignExperimental clinical trial with the cooperation of volunteers.SettingAcademic medical center.PatientsEleven volunteers (9 men, 2 women; mean age 38 years; 3 had symptoms of GERD).InterventionsThe Bravo system was introduced into the esophagus and stomach along a thin endoscope and capsules were attached, one each to the esophageal and gastric walls under direct vision through the endoscope. Esophageal and gastric pHs were simultaneously monitored.ResultsThe 2 capsules were successfully placed in 10 of the 11 subjects, and both esophageal and gastric pHs were monitored for 48 hours in 9 subjects. Mild to moderate precordial pain was observed in 7 subjects, but no other complications or side effects were observed in this study. The gastric pH of 10 subjects increased after meals and returned to baseline pH 2 hours later. Decrease of esophageal pH was observed 1 hour after a meal in the symptomatic subjects and corresponded to the time when gastric pH decreased secondary to the increase of pH with meals.ConclusionsThe Bravo capsule is easily placed on the gastric wall under endoscopic assistance and enables long ambulatory monitoring of gastric pH.